Rationally Designed Complex, Hierarchical Microarchitectures

Abstract

Falling Out During simple precipitation, molecules fall out of solution from locations of highest concentration and, consequently, the shape of the precipitate will be dictated by its crystallization thermodynamics. Noorduin et al. (p. 832 ; see the Perspective by Vlieg ) designed micrometer-scale structures by varying the reaction conditions for silica and carbonate precipitation in which precipitation changes the local concentration and acidity to alter the next stage of precipitation, thus controlling whether the solid phase grows toward or away from the bulk solution. The result is the ability to design and generate a variety of complex structures by simple reaction-diffusion processes.